The explosion blasted out the windows at Shepherd ElectricSupplyas pieces of the ceiling rained down and the building groaned.

Roger Sampson, an employee, had lived in earthquake-prone Los Angeles for eight years and felt a quake shake Maryland two years ago. But Tuesday afternoon, when a freighttrain and a truck carrying garbage collided in Rosedale just blocks from the warehouse, was different.

Workers in the building in the 7400 block of Pulaski Highway were shaking with fear, Sampson said, and he saw a few of his co-workers bleeding, one from the neck, after being hit by glass.

"That was pretty scary," Sampson said. "I've never experienced an explosion, this was a different feeling. We didn't know what was going on."

As dozens of first responders arrived, Sampson left to pick up his daughter from school. "I'm grateful that I didn't get hurt," he said.

The explosion after the train derailed near the 7500 block of Lake Drive in an industrial area in Baltimore County was felt as far north as Harford County as far south as Anne Arundel County. It frightened employees and residents nearby as huge clouds of black smoke filled the sky. The operator of the truck was in serious condition at Maryland Shock Trauma Center as of late Tuesday, but no one else in the area was seriously injured, authorities said.

People nearby had varying descriptions of the explosion, which damaged several structures in the vicinity; some were fearful of a terrorist attack.

UPS delivery man Rich Gossman, who was just blocks away from the explosion, said, "It felt like it was about to push me out of my car. My ears are still ringing."

In the Maryland Manor neighborhood, a small community tucked between Pulaski Highway and the train tracks, the accident rekindled simmering resentment of the freight cars that rumble by. Their community partly blocked off, residents walked along the streets, comparing home damage — windows broken, doors blown off, foundations cracked, and shelves rocked off the walls with their shattered tchotchkes on the floor.

"They shouldn't be allowed to bring this kind of cargo here," said Wes Lego, 64, a retired Amtrak foreman, whose home lost all but about five of its windows and gained cracks in the foundation. His is one of the homes closest to the tracks.

"There's no gates. I see kids sitting on the tracks. They need a fence through this neighborhood."

Lego was shooting video of the derailment from a spot just past the edge of the property when the explosion happened.

"I saw this big flash, then I heard a boom," he said. "It knocked me on my ass — it knocked me down."

In residential neighborhoods farther out, houses shook from the explosion.

"My whole window almost came out," said Donta Jackson, 29, who lives on Orchard Ridge Boulevard. "I thought it was a missile, that we were under attack."

Howard Hooke, 61, lives about a half-mile north of the crash scene and said he was planting in his garden when the accident occurred.

"We live by the railroad yard, and sometimes you can hear the cars when they all start cranking," he said. "I thought, 'If that didn't sound like metal-to-metal.'"

The blast, Hooke said, knocked over shelves of cleaning supplies in his garage. He said there had been no police presence or warnings in his neighborhoodin the wake of the derailment.

Charlene Spilker, office manager at Accurate Termite & Pest Control, was on the phone when she heard what sounded "like a bomb," while Michelle Dean of Essex also thought it was a terrorist attack and that they were "dropping bombs."

The office on Philadelphia Road — about a mile from the scene — rattled, and Spilker ran out the back door, thinking something had hit the front of the building.

"I was afraid of what I was going to see," Spilker said. "I looked up and there was a big cloud of black smoke."

As several helicopters circled in the sky Tuesday afternoon, onlookers gathered near the corner of 66th Street and PulaskiHighway, many capturing photos of black smoke rising into the air with their camera phones.

At Northeastern Supply, another warehouse a few blocks from the derailment, Lori Everson was sitting in her office and heard the explosion, which knocked items from the shelves. She said she thought a vehicle from Pulaski Highway had driven into her building.

About 50 employees at the warehouse ran outside and watched a huge plume of black smoke fill the sky, Everson said.

Everson and her co-workers went back inside to watch the coverage of the derailment on television. They had scratchy throats and burning eyes from the smoke, she said.

In the small community north of Philadelphia Road near the crash site, residents were still in wonder at the scale of the blast, but were not worried about leaving a few hours later.

The communities off Longview Avenue, Wilhelm Avenue and Summit Avenue were within the 20-block optional evacuation radius, but the westerly wind carrying smoke toward Baltimore City put some residents at ease.

Fred Snyder, 49, said he would continue to monitor the wind direction. As long as the smoke stayed away, he felt comfortable staying home.

"They say this is going to last all night," Snyder said. "If it starts shifting, then maybe I'll think twice."

Anna Valentine, 83, was in her kitchen, sitting next to her husband, when she heard "boom!" and had to calm herself so she wouldn't have a heart attack, she said. She wears a hearing aid and worried her eardrums would blow out.

In the early evening, residents of Maryland Manor gathered in their yards as smoke still rose above their neighborhood. Boys skateboarded in the street, and emergency vehicles made their way through the local roads.

"I'm really concerned about the fumes," said resident Delores O'Neil, a county school bus driver.

O'Neil said she wanted to stay in her home rather than evacuate. She came home to shattered glass in her den, where frames holding pictures of her son's wedding and her grandchildren had been knocked off the walls in the blast.

"It kind of makes me sad," she said, looking at a small pile of glass on the floor. "It could have been worse."

Vincent Chiu, manager of Ha Ha Food Market near Pulaski Highway and 66th Street, just a few blocks from the crash site, said glass doors were blown off their tracks, boxes of food fell from shelves and the kitchen ceiling fell in.

"The whole ceiling here, there were people working in here when the whole ceiling fell," Chiu said. "They were making dim sum."